1. Field of the Invention
The invention relates generally to media for interconnecting computer network devices, such as computers, hubs, and servers. More particularly, the apparatus herein utilizes two otherwise unused pairs of wires in an existing network interconnection cable, to provide a second communication channel, or link. Use of the second channel doubles the effective bandwidth of the communication link between the network components, thereby eliminating "bottlenecks" and delays in data transfer.
2. Description of Prior Art
Networks are typically used where many personal computers, printers, plotters, FAX machines, scanners, and file servers must function conjunctively in a work environment. The network allows the devices or components of the system to be interconnected, so that data can be accessed and transferred throughout the system. The network also permits users to share network devices, such as printers, FAX machines, and the like.
A computer network which encompasses a relatively small area is known as a local-area network, or LAN. Most LANS are restricted to a single building, or a group of adjacent buildings. However, any number of LANS can be interconnected to each other over any distance by using telephone lines or radio frequency transmissions. A group of LANS connected in the manner is called a wide-area network, or WAN.
Different types of LANS have been developed over the years, differing principally in topology, protocols, and media.
Topology refers to the geometric arrangement of devices in the network. For example, network components may be arranged in a bus or straight line, in a star pattern, or in a ring-like configuration.
Protocols pertain to the rules and encoding specifications for sending and receiving data throughout the network. Protocols also determine whether the network employs a peer-to-peer architecture, where equal responsibilities are assumed by each node, or a client/server architecture, where clients rely upon servers for network resources.
The media of a network is the method by which the devices are interconnected. Commonly used media include twisted-pair wire, coaxial cables, fiber optic cables, or radio frequency transmissions.
The Ethernet protocol, originally developed in 1976, remains one of the most common protocols still used today. An Ethernet network uses either a bus or star topology, and supports data transfer rates ranging from 10 to 1000 Mbps (Megabits/second). The Ethernet specification served as the basis for the IEEE (Institute of Electrical and Electronic Engineers) 802.3 standard. This standard specifies the physical and lower software layers required for data transfer in an Ethernet network. The Ethernet also uses the CSMA/CD (Carrier Sense Multiple Access/Collision Detection) access method, to handle overlapping and simultaneous device access to the network.
The 10Base T (10 Mbps) and 100Base-T (100 Mbps) sections of the IEEE 802.3 CSMA/CD standard describe the mechanical and electrical characteristics of interconnections for the network devices. These characteristics include a point-to-point connection between devices, using a cable having a predetermined maximum length. The cable consists of four wire pairs ("twisted pairs"), contained in a common sheathing. A standardized electrical connector (RJ-45) and a wiring assignment for that connector are also specified. For 10Base T and 100Base-T, the IEEE 802.3 standard specifies the use of only two of the four twisted pairs of wires. While the interconnection of the unused twisted pairs to the standardized connector is specified, their use is not.